This application is related to United States Patent Applications entitled A SYSTEM, METHOD AND ARTICLE OF MANUFACTURE FOR A DEVELOPMENT ARCHITECTURE FRAMEWORK and A SYSTEM, METHOD AND ARTICLE OF MANUFACTURE FOR MAINTENANCE AND ADMINISTRATION IN AN E-COMMERCE APPLICATION FRAMEWORK, both of which are filed concurrently herewith and which are incorporated by reference in their entirety.
The present invention relates to improving system performance and more particularly to detecting and cleaning up orphaned server contexts.
An important use of computers is the transfer of information over a network. Currently, the largest computer network in existence is the Internet. The Internet is a worldwide interconnection of computer networks that communicate using a common protocol. Millions of computers, from low end personal computers to high-end super computers are coupled to the Internet.
The Internet grew out of work funded in the 1960s by the U.S. Defense Department""s Advanced Research Projects Agency. For a long time, Internet was used by researchers in universities and national laboratories to share information. As the existence of the Internet became more widely known, many users outside of the academic/research community (e.g., employees of large corporations) started to use Internet to carry electronic mail.
In 1989, a new type of information system known as the World-Wide-Web (xe2x80x9cthe Webxe2x80x9d) was introduced to the Internet. Early development of the Web took place at CERN, the European Particle Physics Laboratory. The Web is a wide-area hypermedia information retrieval system aimed to give wide access to a large universe of documents. At that time, the Web was known to and used by the academic/research community only. There was no easily available tool which allows a technically untrained person to access the Web.
In 1993, researchers at the National Center for Supercomputing Applications (NCSA) released a Web browser called xe2x80x9cMosaicxe2x80x9d that implemented a graphical user interface (GUI). Mosaic""s graphical user interface was simple to learn yet powerful. The Mosaic browser allows a user to retrieve documents from the World-Wide-Web using simple point-and-click commands. Because the user does not have to be technically trained and the browser is pleasant to use, it has the potential of opening up the Internet to the masses.
The architecture of the Web follows a conventional client-server model. The terms xe2x80x9cclientxe2x80x9d and xe2x80x9cserverxe2x80x9d are used to refer to a computer""s general role as a requester of data (the client) or provider of data (the server). Under the Web environment, Web browsers reside in clients and Web documents reside in servers. Web clients and Web servers communicate using a protocol called xe2x80x9cHyperText Transfer Protocolxe2x80x9d (HTTP). A browser opens a connection to a server and initiates a request for a document. The server delivers the requested document, typically in the form of a text document coded in a standard Hypertext Markup Language (HTML) format, and when the connection is closed in the above interaction, the server serves a passive role, i.e., it accepts commands from the client and cannot request the client to perform any action.
The communication model under the conventional Web environment provides a very limited level of interaction between clients and servers. In many systems, increasing the level of interaction between components in the systems often makes the systems more robust, but increasing the interaction increases the complexity of the interaction and typically slows the rate of the interaction. Thus, the conventional Web environment provides less complex, faster interactions because of the Web""s level of interaction between clients and servers.
A system, method and article of manufacture are provided for detecting an orphaned server context. A collection of outstanding server objects is maintained and a list of contexts is created for each of the outstanding server objects. A compilation of clients who are interested in each of the outstanding server objects are added to the list. Recorded on the list is a duration of time since the clients invoked a method accessing each of the contexts of the outstanding server objects. The list is examined at predetermined intervals for determining whether a predetermined amount of time has passed since each of the objects has been accessed. Contexts that have not been accessed in the predetermined amount of time are selected and information is sent to the clients identifying the contexts that have not been accessed in the predetermined amount of time.
In one embodiment of the present invention, after waiting a preselected amount of time for receiving a response from one of the clients, the context may be deleted if a response from one of the clients is not received within the predetermined amount of time. In another embodiment of the present invention, a response may be received from one of the clients requesting that one of the contexts be maintained. In such an embodiment, upon receipt of the response, a time the context was last updated may be updated to a current time.
In a further embodiment of the present invention, a queuing delay may be accommodated for a response from the clients. In one aspect of the present invention, each of the clients may maintain a collection of all objects the client is interested in. The clients then may send requests to keep alive any objects the clients are currently interested in.